Radiation from accelerated impurities in a Bose–Einstein condensate

We investigate radiation spectra arising from accelerated point-like impurities in the homogeneous Bose–Einstein condensate. A general formula for the radiation spectrum is obtained in the integral form as a function of given impurity trajectory within the Bogoliubov approximation. The Planckian spectrum is obtained for a special accelerated motion, which is shown to be unphysical. Non-Planckian spectrum is found in the case of a uniformly accelerated impurity. We compare our result with similar settings discussed in other quantum systems.

► We analyze radiation spectra emitted from accelerated impurities in a BEC.
► A thermal radiation is found in a certain mathematical limit as a special case.
► We discuss that this limit is not justified from experimental stand.
► Non-thermal radiation is found for the case of relativistic uniform acceleration.